1. Field
The present disclosure relates to a water electrolysis system.
2. Description of the Related Art
Fuel cells produce electricity by using hydrogen gas, for example, as fuel gas. Water electrolysis apparatuses are widely used in the production of the hydrogen gas. A water electrolysis apparatus uses a solid polymer electrolyte membrane to generate hydrogen (and oxygen) by electrolysis of water. Electrode catalyst layers are disposed on respective opposite sides of the solid polymer electrolyte membrane to constitute a membrane electrode assembly. Current collectors are disposed on respective opposite sides of the membrane electrode assembly to constitute a unit.
A plurality of such units are stacked, and a voltage is applied across the stack while water is supplied to anode current collectors. Thus, the water is electrolyzed to generate hydrogen ions (protons) on the anode side of the membrane electrode assembly. The hydrogen ions move through the solid polymer electrolyte membranes to the cathode side, where the hydrogen ions combine with electrons to generate hydrogen. On the anode side, oxygen generated together with hydrogen is discharged with excess water from the units.
As disclosed in Japanese Unexamined Patent Application Publication No. 2011-225964, for example, a water electrolysis system of this type includes a water electrolysis apparatus and a casing having a housing chamber that houses the water electrolysis apparatus. The casing has a first electric component chamber and a second electric component chamber that are separate from the housing chamber. The first electric component chamber houses a first electric component and includes a fan for introducing external air. The second electric component chamber houses a second electric component and communicates with the first electric component chamber through a pipe.